Wheel Reviews
Bontrager Aeolus 5 D3 Exhaustive CFD
Modeling and testing led Bontrager to design a range of wheels that are shallower than competitors' wheels. Bontrager claims this is because its wind-tunnel tests show its 35mm Aeolus 3 actually rates a class higher, offering comparable aerodynamics to a traditional 45mm wheel. But because the company won't offer the Aeolus 3 in a clincher version until summer, we tested the 50mm-deep Aeolus 5, which is closer in actual size to Zipp's 303 and Hed's Jet 4 wheels.
Unlike Zipp, Bontrager claims center of pressure has a negligible effect on handling; the primary factor, the company says, is rim depth. So designers' focus is on building shallower rims, which they claim are as fast as a deeper rim from a competitor and easier to handle. Bontrager's wheels may be faster, but the Aeolus 5 was the flightiest in crosswinds of the three we tested. That could be due to the greater depth or the shape of the cross section. But the Aeolus's handling, while a clear improvement over a traditional V-shaped rim, lacked the smoothness of the other wheels in this test.
The Aeolus 5s were snappy in climbing and solid under hard cornering, and delivered a more damped ride than some carbon wheels. Braking was smooth, but Bontrager's included cork-based pad had a spongy, indistinct feel at the lever. Modulation and feel improved when we swapped to gray Zipp/SwissStop pads.
- Price: $2,700
- Weight: 730g, front; 870g, rear
- Rim Depth: 50mm brake-track
- Width: 26mm
- Widest point: 27mm
Hed Jet 4 FR
Hed proudly sticks with tried-and-true aluminum brake tracks. Given the results, why switch? The gorgeous Jet 4 FR wheels are the same weight as the Bontragers, handle beautifully, and cost $800 less than the Zipp or Bontrager sets.
Steve Hed says that because his aluminum wheels are close to carbon in weight, he chooses to offer more-affordable wheels and focus on aerodynamics. The Jet 4 uses the same 18-front-/24-rear-spoked C2 scandium rim as the company's Ardennes model, with a carbon-fiber fairing. The rear Carbon FR Sonic hub has a grease port for easy maintenance. The carbon fairing is delicate, so take care when using a roof rack's wheel strap.
In testing, the Jet 4 proved equal to the Zipps in handling crosswinds. The gently radiused profile made them less susceptible to buffeting crosswinds than most aero wheels.
They're 100 grams heavier than the Zipps, but most of that difference is in the rear hub, so they still climb well, no surprise because the design is based on the Ardennes SL, a favorite all-around clincher. The scandium brake track is grippy, boosting our confidence on descents.
The spoke nipples anchor inside in the rim, under the fairing, which makes truing a hassle. But the longer spokes also give the wheel a more compliant ride without sacrificing lateral stiffness.
Price: $1,900 Weight: 700g, front; 910g, rear Rim Depth: 45mm brake-track Width: 23mm Widest point: 26mmZipp 303 Firecrest
The latest addition to the Firecrest line, the all-carbon 303 clinchers (pictured on p. 26) have impressive finish quality and the same hubs found on other Zipp wheels. A 2011 redesign of the rear hub pushed the nondrive-side hub flange and cartridge bearing 7.5mm outboard, creating a stiffer wheel.
Our first test ride on the Firecrest occurred in gusty crosswinds up to 40mph. On a straight, slightly downhill section exposed to the wind, the wheels displayed only slightly more buffeting than a standard box-section rim. Later test rides bore out that initial impression: The 303s are exceptionally stable even in strong crosswinds. On local climbs, the wheels lacked the snap of a lightweight climbing wheel, but we never felt their heft was holding us back. Even on steeper sections, they responded quickly to out-of-the-saddle efforts. They were the stiffest-riding wheels in this test, but not uncomfortably so.
No carbon clincher rivals the performance of an aluminum braking surface, but these are among the best we've found. There was no pulsing under even hard, sustained braking, and the new gray pad from SwissStop that comes with the Firecrests is the best carbon-specific pad we've ever used. Paired with SRAM brakes, it was powerful without being grabby and never lost its positive feel.
- Price: $2,700/pair
- Weight: 690g, front; 820g, rear
- Rim Depth: 45.5mm brake-track
- Width: 26mm
- Widest point: 28mm
Conclusions
Each of these three sets is ideal for different riders.
- The Zipps are the lightest at 1,510 grams, and were the easiest to handle. They're hard to beat as an all-around upgrade wheel. But they're pricey and don't have quite the braking performance of the Jet 4s.
- The Heds had the most comfortable ride of the three, handle as well as the Zipps, and the security of a metal brake makes them ideal for anyone who likes to go downhill fast. They're also the most affordable, by far. But the carbon fairing is delicate compared with a structural carbon rim, although damage to the fairing doesn't necessarily mean the wheel is compromised.
- The Bontrager wheels have a compelling aero story, backed by what the company says is apples-to-apples wind-tunnel comparisons. Bontrager's claims that its wheels ride shallower than their actual dimensions mean that the Aeolus may be a good choice for multisport athletes who stand to gain more from an aerodynamic advantage, and will benefit from the wheels' bike-stabilizing qualities.
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